EP4091447A1 - Gel used as a plant growth regulator and/or herbicide - Google Patents

Abstract

The present invention relates to a plant growth regulator and a herbicide. More particularly, the present invention relates to the use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and/or herbicide. The present invention also relates to plant growth regulating and/or herbicidal compositions and methods.

Description

Technical field of the invention

The present invention relates to a plant growth regulator and a herbicide. More particularly, the present invention relates to the use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and/or herbicide. The present invention also relates to plant growth regulating and/or herbicidal compositions and methods.

State of the prior art

The use of glyphosate as a herbicide is increasingly contested by regulatory authorities and the general public.

The alternatives to glyphosate available to farmers are manual or mechanical. Several are already used by French local authorities, which can no longer use glyphosate in spaces open to the public since January 2017.

In particular, there are preventive methods, such as crop rotation (which makes it possible to regularly break the development of weeds, which are different depending on the plants grown), false sowing (preparing the fields several weeks before sowing to allow weeds to weeds to germinate, and eliminate them mechanically before actually sowing), or even mulching (which consists of covering the soil with materials of plant and mineral origin, or with certain synthetic materials, to stop the growth of weeds).

Mechanical means can also stem the growth of weeds by pulling out or destroying the roots of unwanted plants. There are different kinds machines depending on the crops and their specificities, some cutting the roots several centimeters deep, others using harrows, which act on the surface soil. Farmers can also practice thermal weeding, passing flames, hot water or steam over weeds to kill them.

However, these methods have drawbacks. In particular, they affect the structure of the soil and can increase its erosion. They also require substantial energy expenditure, and are not all suitable for large farms.

For now, there is no biological product that has an equivalent effectiveness to glyphosate.

Therefore, finding an alternative solution to the use of glyphosate represents a major strategic challenge.

To be accepted, this alternative must have an equivalent or even superior efficacy to glyphosate and not be harmful to the environment or to human health. Ideally, in addition to a weedkiller action, the product should have a growth regulator action to limit the number of seasonal applications and the clearing and mechanical mowing stages.

The action of nonanoic acid (also called pelargonic acid) is known as a growth regulator and/or herbicide.

The applicants have already proposed the use of nonanoic anhydride as a growth regulator and/or herbicide. Although this use has many advantages, the formulation of these compositions still needs to be refined in order to increase their effectiveness.

Presentation of the invention

The present invention proposes to solve the problems described above.

Thus the present invention relates to the use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and/or herbicide.

The applicant has been able to demonstrate that a gel according to the invention does not behave like a solution of nonanoic acid or like nonanoic anhydride alone. This formulation has greater efficacy, in terms of intensity and duration, than that of nonanoic acid.

The presence of the polymer and of the water in the gel according to the invention acts as a reservoir of nonanoic acid which will be able to act longer than if it had been spread alone. The present invention also relates to a gel comprising nonanoic anhydride, a polymer and water.

According to a preferred embodiment of the invention, said herbicide is a foliar herbicide.

According to a preferred embodiment of the invention, said herbicide is a root herbicide.

According to a preferred embodiment of the invention, said nonanoic anhydride is at a concentration greater than 30% by weight.

According to a preferred embodiment of the invention, the aqueous solution according to the invention comprises said nonanoic anhydride is at a concentration of between 30% and 85% by mass.

According to a preferred embodiment of the invention, said aqueous solution comprises water at a concentration of less than 70% by weight.

According to a preferred embodiment of the invention, said aqueous solution comprises water at a concentration of between 15% and 70% by mass.

In the context of the present invention, the term "polymer" refers more particularly to a water-soluble polymer

According to a preferred embodiment, said polymer is chosen from the group consisting of Poly(phenylene oxide) (PPO), Polypropylene glycol (PPG), Polycaprolactone (PCL), Polylactic acid (PLA), Polyglycolic acid (PGA), polyester, polyamide, polyacrylate, polyurethane and their mixtures. According to a preferred embodiment of the invention, said polymer is polyethylene glycol.

According to a preferred embodiment of the invention, said polyethylene glycol is at a concentration greater than 5% by mass.

According to a preferred embodiment of the invention, said polyethylene glycol is at a concentration of between 20% and 30% by mass.

According to a preferred embodiment of the invention, said polyethylene glycol has a molar mass greater than 3000 g.mol ^-1 , preferably between 3000 and 10000 g.mol ^-1 , even more preferably between 5000 and 7000 g.mol ^-1 and quite preferably equal to 6000 g.mol ^-1 .

The present invention also relates to a method for the regulation of the growth of plants or the fight against harmful plants, characterized in that one applies to the plants, parts of plants, seeds of plants or to an area an effective quantity of a solution according to the invention. In the context of the present invention, the term "growth regulator" refers to a product and/or a process causing lower growth of all or part of a plant compared to the same type of plant grown under the same conditions. in the absence of said product and/or process. According to a preferred embodiment of the invention, said herbicide is a foliar herbicide.

In the context of the present invention, the term “foliar herbicide” refers to the fact that the herbicidal effect is obtained in particular after contact between the nonanoic anhydride and the leaves of the plant to be treated.

According to a preferred alternative or complementary embodiment of the invention, said herbicide is a root herbicide.

In the context of the present invention, the term “root herbicide” refers to the fact that the herbicidal effect is in particular obtained after contact between the nonanoic anhydride and the roots of the plant to be treated.

The present invention also relates to a method for regulating the growth of plants or a method for combating harmful plants, characterized in that the plants, parts of plants, seeds of plants or an area are applied with a quantity effective of a solution according to the invention.

In the context of the present invention, the term “effective amount” refers to an amount of product that makes it possible to obtain the desired herbicidal and/or growth regulator effect.

• [Fig. 1] montre l'action d'une composition comprenant de l'anhydride nonanoïque, du PEG6000 et de l'eau, comparée à celle d'une composition comprenant de l'acide pelargonique, du PEG6000 et de l'eau pulvérisée par spray à une dose de 0.05 l/m² sur les feuilles d'adventices de différents types d'adventices herbacés.
• [Fig. 2] montre l'action d'une composition comprenant de l'anhydride nonanoïque, du PEG6000 et de l'eau, comparée à celle d'une composition comprenant de l'acide pelargonique, du PEG6000 et de l'eau pulvérisée par spray à une dose de 0.035 l/m² sur les feuilles d'adventices de différents types d'adventices herbacés.
• [Fig. 3] montre l'action d'une composition comprenant de l'anhydride nonanoïque, du PEG6000 et de l'eau, comparée à celle d'une composition comprenant de l'acide pelargonique, du PEG6000 et de l'eau pulvérisée par spray à une dose de 0.02 l/m² sur les feuilles d'adventices de différents types d'adventices herbacés.

Preferably, said effective quantity is greater than 5 g, preferably 10 g and even more preferably 15 g of nonanoic anhydride per m ² of surface to be treated.

• [ Fig. 1 ] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.05 l/m ² on weed leaves of different types of herbaceous weeds.
• [ Fig. 2 ] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.035 l/m ² on weed leaves of different types of herbaceous weeds.
• [ Fig. 3 ] shows the action of a composition comprising nonanoic anhydride, PEG6000 and water, compared to that of a composition comprising pelargonic acid, PEG6000 and water sprayed at a dose of 0.02 l/m ² on weed leaves of different types of herbaceous weeds.

Detailed description of the invention

The use according to the invention can be implemented on any type of surface (natural or artificial) and more particularly on roads, verges, access roads, car parks, railways, green spaces and terraces. The solution, for use according to the invention, may further comprise additional agents such as penetration enhancers, colorants, emulsifiers, dispersants, wetting agents, binders, thickeners and/or preservatives.

The concentration of nonanoic anhydride in the formulations that can be used in the context of the present invention can be easily estimated by those skilled in the art. However, it has been shown that concentrations greater than 10%, preferably greater than 20% and even more preferably between 30 and 50% by mass would make it possible to obtain sufficient effectiveness.

In the context of the present invention, a mass percentage refers to a quantity in grams of pure nonanoic anhydride per 100 g of total mass of said solution.

The liquid formulations which can be used in the context of the present invention can comprise one or more solvents. Surfactants can be used as penetration enhancers, emulsifiers, dispersants, wetting agents or others used in the formulation.

The quantity of surfactant used is generally from 0.1 to 50% by mass, preferably from about 0.1 to 25% by mass, relative to a total quantity of the solution.

According to a preferred embodiment, the solution according to the invention further comprises a dye, preferably a dye of natural origin. According to an entirely preferred embodiment, said dye is chlorophyll.

This last embodiment, the presence of a dye makes it possible to compensate for the loss of coloring, of the treated surface, linked to the disappearance of the plants. The presence of said dye also makes it possible to mask the presence of the treated plants by using a dye of a color similar to that of the treated surface.

A person skilled in the art is able to select the appropriate dye and its concentration according to the characteristics of the treated surface.

Binders and thickeners are well known to those skilled in the art. These are, for example, dextrin, carboxymethylcellulose salts, polyvinylpyrrolidone, polyvinylalcohol, sodium mannitol and sorbitol.

The method according to the invention is similar to a conventional application method for known agricultural chemicals and includes, for example, aerial spraying, soil spreading or application to foliage.

The use according to the invention can be implemented alone or with at least one other herbicide, growth regulator plants, fungicide, insecticide, acaricide, nematocide or mixture thereof.

Examples

/Foliar use.

Different varieties of plants were grown under controlled light, temperature and humidity conditions. More particularly, said plants were subjected to cycles of 8 hours of nights (at 18° C.) and 16 hours of days (at 23° C.) at a constant humidity of 70% (+/- 20).

• de l'anhydride nonanoïque (38%), du PEG 6000 (24.8%), et de l'eau (37.2%), ou
• de l'anhydride nonanoïque et du PEG 6000, ou,
• de l'acide nonanoïque, du PEG 6000, et de l'eau, ou
• et un herbicide de l'art antérieur (Herbistop super^®) comme témoin positif.

These varieties were treated with solutions including:

• nonanoic anhydride (38%), PEG 6000 (24.8%), and water (37.2%), or
• nonanoic anhydride and PEG 6000, or,
• nonanoic acid, PEG 6000, and water, or
• and a herbicide of the prior art (Herbistop ^super® ) as positive control.

Untreated control plants were used as a negative control.

The solutions comprising nonanoic anhydride or nonanoic acid were spread with varying densities (0.05 l/m ² , 0.0351/m ² and 0.02 l/m ² ).

The action of its different compositions was monitored for 14 days with measurements taken at 24 hours, 7 days, 14 days and 30 days. The results obtained are represented in [ Fig. 1], [Fig. 2 ] and [ Fig.3 ]. The rating of the efficacy of the treatment is established by comparison between the treatment evaluated and the untreated control. The percentage of destruction is estimated by the ratio of biomass destroyed/biomass still green and the number of plants still alive from the treated versus the control.

Degradation of the weed is observed after 1 day regardless of the product used. The effects of drying out are visible a few hours after spraying. For all spreading densities, a higher efficiency of aqueous solutions of nonanoic anhydride is observed compared to that comprising nonanoic acid. Furthermore, a constant effectiveness is observed at 14 days of the aqueous solutions of nonanoic anhydride, whereas the effectiveness of the solutions comprising nonanoic acid decreases at 14 days.

Claims (10)

Use of a gel comprising nonanoic anhydride, a polymer and water as a plant growth regulator and/or herbicide. Use according to one of the preceding claims, characterized in that the said herbicide is a foliar herbicide. Use according to one of the preceding claims, characterized in that the said herbicide is a root herbicide. Use according to one of the preceding claims, characterized in that the said nonanoic anhydride is at a concentration greater than 30% by mass. Use according to one of the preceding claims, characterized in that the said nonanoic anhydride is at a concentration of between 30% and 85% by mass. Use according to one of the preceding claims, characterized in that the said polymer is polyethylene glycol. Use according to one of the preceding claims, characterized in that the said Polyethylene Glycol is at a concentration greater than 5% by weight. Use according to one of the preceding claims, characterized in that the said Polyethylene Glycol is at a concentration of between 5% and 30% by mass. Use according to one of the preceding claims, characterized in that the said polyethylene glycol has a molar mass greater than 3000 g.mol ^-1 , preferentially between 3000 and 10000 g.mol ^-1 , even more preferentially between 5000 and 7000 g.mol ^-1 and quite preferably equal to 6000 g.mol ^-1 . Process for regulating the growth of plants or combating weeds, characterized in that applies to the plants, plant parts, plant seeds or to an area an effective amount of a gel comprising nonanoic anhydride, a polymer and water.

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